VM settings reference

VM Settings has six pages (General, Display, Storage, Network, Sharing, Advanced) and a seventh, Cloud-Init, on Linux VMs made from a cloud image. Before saving, MacVisor says when your edits apply: now, or at the next start. On a suspended VM, port forwards and the clipboard direction apply when it resumes.

General

Identity: name, icon, and up to 256 characters of notes shown on the Overview tab.

Resources: vCPU count and memory. Both apply at the next start from shut down; a suspended VM resumes with the earlier values first.

Startup: Start at Login has the background service start the VM headless at each login, whether or not the MacVisor app opens. A VM shut down at logout, the default, boots fresh; with Suspend VMs chosen in Settings → General → Logout and Shutdown, it resumes from its saved state, once the Mac is unlocked if it is locked. See Always-on host.

Window: what closing the VM window does (When the Window Closes: Hide Window, Ask Each Time, or Shut Down VM), and whether the VM opens in its own window by default.

Display

• Headless removes the graphics device, for servers and automation.
• Accelerated Graphics uses Apple's Mac graphics device; macOS guests only. Linux guests use software-rendered Virtio graphics.
• Match Window Size follows the window's size on guests that support it.
• Primary Display: a preset (1080p, 1440p, 4K, Studio Display 5120×2880, Classic 1920×1200) or a custom resolution and PPI.
• Additional Displays: macOS guests; each gets its own window.

Storage

Boot Disk: file name, capacity, and format. The format is not editable: MacVisor creates ASIF and keeps legacy raw disks as they are.

• Resize… grows an ASIF disk, and on a macOS guest also shrinks it. A Linux guest's disk and a layered (linked-clone) disk only grow. On a raw disk the button is Expand… and only grows. A template's disk can't be resized while VMs made from it read it. mvz set <vm> --disk <GiB> grows from the CLI; a cloud-image Linux VM grows its filesystem at the next boot. See Resizing.
• Convert to ASIF… appears for a raw disk on a stopped VM. See Storage and sharing for the free-space rule.
• Bus: Virtio or NVMe, plus caching and synchronisation policy.

Additional Disks: create, attach, resize, or remove extra ASIF images. Removing one moves its image to the Trash. Disk changes need the VM shut down, with no suspended session; the section says what is in the way.

Disk Images: ISOs and raw images attached by path on a chosen bus at the next start. USB-bus images can also be attached while the VM runs, here or on the Overview tab, when Allow Runtime USB Mass-Storage Attach is on. Compressed or sparse .dmg files are not supported.

Network

Primary interface: NAT, bridged (pick the host interface), or a custom network. Additional interfaces add NICs.

Host port forwarding: per-VM TCP or UDP forwards from a host address and port to a guest port, through the guest agent. They apply at once to a running VM with guest tools connected, and to a suspended VM when it resumes. A cloud-image VM also forwards the ports its guest listens on automatically, to 127.0.0.1 at the same number.

See Networking and Custom networks.

Cloud-Init

Linux VMs made from a cloud image only. It shows what cloud-init was given for the first boot: hostname; account (user name, full name, and the UID mirrored from your Mac account); container runtime; whether to install the guest agent; the SSH authorised keys, one per line; and your own user data, applied after MacVisor's.

Editing these after the first boot changes what a re-provisioned guest would get, not the guest you have. To re-provision, turn on Set up again on next start: the next boot runs cloud-init as for a new machine, with a new identity (and possibly a new address).

Sharing

Shared Folders: host folders exposed to the guest under a tag, optionally read-only. Mount them in the guest by tag.

Clipboard: which way the clipboard is shared: Both Ways (the default), Mac to VM Only, VM to Mac Only, or Off. Text and images only; the Mac's clipboard is sent only while the VM's window is active. Applied live, except on a Linux guest using spice-vdagent, where a change to or from Both Ways applies at the next restart. The Overview tab has the same picker, and mvz set <vm> --clipboard both|to-vm|from-vm|off sets it from the CLI. See Guest tools.

Guest Tools: Enable Guest Tools turns on the host side of the agent channel; Attach Guest Tools Image at Boot mounts the MacVisor Agent volume at each start. The channel needs the Virtio Socket (vsock) device under Advanced. Guest tools add devices to the VM, so turning them on or off, here or with the Overview's Guest tools switch, applies at the next start from shut down; a suspended VM resumes as it was saved. See Guest tools.

Rosetta: mounts Rosetta into Linux guests so they can run x86-64 Linux binaries.

Guest-initiated file, URL, and port-forward requests always need your approval, whatever these settings say.

Advanced

Keyboard and Pointer: a Mac keyboard and Mac trackpad for macOS guests; a USB keyboard and pointing device stay attached as a fallback.

Input Capture: Capture system keys sends shortcuts such as ⌘Tab to the guest; Control-Command or Control-Option hands control back.

Sound: output and input are separate Virtio devices. Microphone input asks for macOS microphone permission the first time the guest listens.

Performance: the memory balloon, and nested virtualization on an M3 or later Mac. Both are on by default for Linux VMs made from a cloud image. A running VM's balloon target is set in GiB on the Overview tab or with mvz set <vm> --balloon-target <GiB>. It stays between the VM's memory and a floor: a quarter of the memory, and at least 1 GiB (4 GiB for a macOS guest). Below half the memory, the Overview asks first.

Automatic Setup (first boot): macOS 27 guests: create the first account (mac / macvisor by default; the New VM form remembers the account name you used last, not the password), sign it in automatically, and turn on Remote Login, skipping Setup Assistant. With Remote Login on, MacVisor installs the guest agent after the first boot, authorises your SSH keys, and then turns SSH password logins off. Ignored once the guest has been set up.

NVRAM: a shut-down macOS guest's NVRAM variables, such as boot-args (-v for a verbose boot). A wrong value can keep the guest from booting. macOS 27 currently refuses the private interface this uses; the section says so, as does mvz nvram <vm>, and MacVisor stops trying until macOS is updated. Where it works, a change is written to a copy of the NVRAM first and kept only if it completes, so a failed change leaves the variables as they were.

USB: devices to capture automatically when plugged in while the VM runs; or connect one on demand from the USB button in the VM window.

Firmware (Linux): Secure Boot boots only signed kernels; shim-signed distributions work. Turning it off keeps the enrolled keys.

Devices

Toggling a device changes the VM's topology: it applies at the next start from shut down, and a suspended VM resumes with the devices it was saved with.